芦荟苷通过下调HMGB1的表达抑制乳酸诱导的胃癌细胞增殖和迁移

目的 探讨芦荟苷对乳酸诱导胃癌细胞增殖和迁移的抑制作用及可能的分子机制。方法 胃癌BGC-823细胞常规培养，实验分为对照组、乳酸组、不同浓度芦荟苷和乳酸联合组，分组处理后的BGC-823细胞，EdU实验检测胃癌细胞的增殖；克隆形成实验检测细胞克隆形成能力；划痕实验和tranwell 实验检测细胞迁移能力；Western blot检测CyclinD1、CyclinE1、PCNA、N-cadherin、E-cadherin、MMP-2、MMP-9和HMGB1的表达；ELISA检测HMGB1的释放。HMGB1干扰质粒和阴性对照质粒分别转染BGC-823细胞，转染48 h后用乳酸刺激细胞24 h，EdU和划痕实验分别检测细胞的增殖和迁移能力。结果 EdU结果表明，芦荟苷明显抑制乳酸诱导的胃癌细胞增殖；克隆形成结果表明，芦荟苷和乳酸联合处理的胃癌细胞，细胞克隆数目显著少于乳酸处理组（P<0.05）；划痕和transwell结果均表明，芦荟苷能够抑制乳酸诱导的胃癌细胞迁移（P<0.05）；Western blot结果表明，芦荟苷能够下调乳酸诱导的Cyclin D1，E1，PCNA，N-cadherin，MMP-2，MMP-9和HMGB1的表达；逆转乳酸对E-cadherin表达的抑制作用；ELISA结果发现，芦荟苷有效阻止了乳酸诱导的HMGB1释放（P<0.05）。EdU和划痕结果表明，敲除HMGB1的BGC-823细胞，乳酸诱导的增殖和迁移与阴性质粒转染组相比明显下降。结论 芦荟苷通过下调乳酸诱导的HMGB1表达、释放以及增殖和迁移相关蛋白的表达，抑制乳酸诱导的胃癌细胞的增殖和迁移。

Aloin inhibits lactate-induced proliferation and migration of gastric cancer cells by down-regulating HMGB1 expression

Objective To assess the inhibitory effects of aloin on lactate-induced gastric proliferation and migration of cancer cells and explore the underlying molecular mechanism. Methods Gastric cancer BGC-823 cells were treated with aloin, lactate or the combination of lactate and different doses of aloin. EdU assay was used to detect the proliferation of BGC-823 cells, and colony formation ability of the cells was evaluated with colony forming assay; wound healing and Transwell assays were used to detect the changes in migration ability of the treated cells. The expression levels of cyclin D1, cyclin E1, PCNA, N-cadherin, E-cadherin, MMP-2, MMP-9 and HMGB1 were determined using Western blotting, and ELISA was performed to detect HMGB1 release. HMGB1 expression was knocked down in BGC-823 cells using RNA interference technique, and the effects of HMGB1 knockdown on proliferation and migration of the cells stimulated with lactate for 24 h were examined using EdU and wound healing assays. Results Aloin treatment significantly inhibited lactate-induced proliferation of gastric cancer cells, lowered the colony forming ability of lactate-treated cells, and suppressed lactate-induced migration of the cells. Treatment with lactate obviously up-regulated the expressions of cyclin D1, cyclin E1, PCNA, N-cadherin, MMP-2, MMP-9 and HMGB1, which were significantly inhibited by aloin; aloin significantly reversed inhibition of E-cadherin and blocked the release of HMGB1 in lactate-treated cells. BGC-823 cells with HMGB1 knockdown, as compared with the cells transfected with the negative control plasmid, showed significantly lowered proliferation and migration abilities following lactate treatment. Conclusion Aloin inhibits lactate-induced proliferation and migration of gastric cancer cells by down-regulating the expression and release of HMGB1 and the expressions of proliferation- and migration-related proteins.